Gasifying of heavy oils through partial combustion



JuEy 17, 1934. c. CHILOWSKY 1,965,610

GASIFYING OF HEAVY OILS THROUGH PARTIAL COMBUSTION 4 SheetsShe et 1 Filed March 20, 1931 Jufly 17, 1934. c. CHILOWSKY GASIFYING OF HEAVY OILS THROUGH PARTIAL COMBUSTION Filed March 20, 1951 4 Sheets-Sheet 2 5 Am m lllllltlllll V Juiy 17, 1934. c. CHILOWSKY GASIFYING OF HEAVY OILS THROUGH PARTIAL COMBUSTION Filed March 20, 1931 4 Sheets-Sheet 3 July 17, 1934. c. CHILOWSKY GASIFYING OF HEAVY OILS THROUGH PARTIAL COMBUSTION Filed March 20. 1931 4 ts-she t 4 4. Z/// I r Patented July 17, 1934 UNITED STATES GASIFYING OF HEAVY OILS THROUGH PARTIAL COMBUSTION Constantin Chilowsky, Paris, France Application March 20, 1931, Serial No. 524,092 In France March 29, 1930 3 Claims.

My invention relates to the process for gasifying heavy oils which consists in atomizing the oil by means of hot air in an unobstructed chamber comprising a crucible or a deflector located opposite the atomizer and in which the oil is subjected to a partial combustion with said air.

In the course of my experiments on that subject I have found out what follows: On the one hand if this thermal conversion is carried out at too low a temperature (approximately less than 800 C.), the gases that are obtained contain a notable percentage of tar, which makes it diflicult to purify them. On the other hand the use of temperatures ranging from 1000 to 1100 C. or of higher temperatures results in the production of carbonaceous deposits if the gases remain a certain time in the combustion chamber.

Now I have found out that this production of carbonaceous deposits could be considerably reduced or even done away with if one succeeded in constantly maintaining a certain amount of oxygen, preferably 1 or 2 per cent, in the hot gases. Maintaining that amount of oxygen was all the more diflicult as thermal conversion took place at a higher temperature.

The improvement according to my present invention consists essentially in carrying out the above mentioned process at temperatures substantially comprised between 1000 and 1100 C. while submitting the gases to a drop of temperature of about 100 to 300 C. immediately upon their issuing from the combustion chamber.

It results therefrom that, generally, partial combustion is not completed, that is, does not spend the whole amount of oxygen present in the mixture of oil and air, so that the gases that are produced still contain a slight percentage of oxygen. Under these conditions the partly cooled gas eventually containing a small percentage of oxygen may circulate in the preheater without producing carbonaceous deposits therein.

In an embodiment of my invention, in order to accelerate the outflow of the gases from the combustion chamber, said gases are evacuated therefrom as soon as the atomized jet has met the bottom of the crucible or the deflector. For the eddies that produce a stirring of the gases and determine the completion of the combustion and the subsequent rise of temperature that may result in the production of the carbonaceous deposits, take place after deflection of the atomized iet.

In the preferred embodiment of my invention, the gases issuing from the combustion chamber are cooled by means of the air that serves for the partial combustion. A heat interchanger is used to this effect, the gases being brought into contact with the relatively cold walls of the latter.

Said heat interchanger is so disposed, with respect to the combustion chamber, that it will produce no material decrease of temperature therein, although these two apparatus are very close acting as the heating fluid, are directed immediately upon their issuing from the combustion chamber.

When said chamber is formed by a crucible, the latter is made of a refractory material preferably disposed in an outer metallic casing. The thickness of the refractory material is so chosen as to prevent any thermic exchange between the combustion chamber and the preheater, which, in this case, surrounds the crucible and is made integral therewith. In order to avoid heat losses, the heat interchanger extends along the whole length of the crucible.

The atomization and the partial combustion take place in the crucible, and the products that issue therefrom flow through the annular space that is provided for this. purpose in the heat interchanger.

In order to obviate the drawback according to which the upward flow of the burning gases in the crucible after their being deflected on the bottom thereof might produce eddies which would cause a more complete combustion and a decrease of the percentage of oxygen, I have provided in one embodiment of my invention means for evacuating the hot products, immediately after deflection of the jet of atomized oil and air, through holes in the crucible in the vicinity of the bottom thereof.

In another embodiment of my invention, the crucible is replaced by a mere deflector and the preheater is disposed below the combustion chamber or around it. In that case an insulating wall of suflicient thickness is provided between the chamber and the preheater.

The method of suddenly cooling the gases directly upon their issuing from the combustion chamber which has been above described gives excellent results, that is reduces the formation.

of carbonaceous deposits to a very small amount in the case of the gasifying of heavy oils of the class of gas-oils, which burn rather slowly.

But in the case of the gasifying of oils of the type of fuel-oils whose combustion is very fast, it is difficult to obtain the maintaining of the small percentage of oxygen that is necessary. It is therefore provided in that case to combine the method of sudden cooling of outflowing gases with the already known method that consists in periodically cutting off the flow of oil, so that the hot air whose flow is kept constant may burn the carbon deposits that may have formed in the combustion chamber and the preheater.

Preferred embodiments of my invention will be hereinafter described with reference to the appended drawings given merely by way of example and in which:

Figs. 1, 2, 3, and 4 are axial sectional views of four different embodiments of combined generators and heat interchangers.

A crucible made of a refractory material 2 is disposed within a gas generator 1 (Fig. 1), the refractory material being preferably enclosed in a metallic casing 3. Opposite said crucible is mounted an atomizer of any suitable type.

The one shown in the drawing is in accordance with the one described in my copending application Ser. No. 503,340 filed Dec. 18, 1930 for Improvements in processes and apparatus for producing heavy oil gas through partial combustion with air.

Said atomizer comprises a central oil inlet conduit 4 and an annular conduit 5 through which hot air flows, said air being fed through tube 6. At the same level as the outlet orifice of conduit 4, a slot 7 is provided, and at a lower level, holes 8 are also provided whose axes make an angle of about 30 with a horizontal plane Ind are substantially convergent.-

The hot products which, after deflection of the jet of atomized oil and air, flow upwardly along the walls of the crucible pass into an annular space 9 provided between wall 3 and partition 10 of a heat interchanger. The other face of this partition 10 is in contact with air introduced through orifice 11 in any suitable manner. After flowing through the heat interchanger said air is conveyed through conduit 13 to tube 6.

Annular spaces 9 and 12 are, in the known manner, so arranged that the fluids that circulate therethrough may follow a helical path. Such an arrangement has been diagrammatically indicated by two spirally wound wires 14 and 15 disposed in spaces 9 and'12, it being not necessary that the spirals should be disposed in opposite directions.

In order to obtain the sudden cooling of the hot products in the heat interchanger it has been supposed in this case that the hot prod-- ucts and the air circulated according to the principle of parallel currents.

In the embodiment of Fig. 2, in which the same reference characters indicate the same parts, the outflow of the hot products takes place immediately after the deflection against the bottom of the crucible of the jet of pulverized oil mixed with air, which reduces the interval of time during which the gases remain in the combustion chamber.

In the generator shown in Fig. 3, the crucible is done away with and combustion chamber 16, for instance of cylindrical shape, merely comprises a deflector 1'7. The hot products, after being deflected, pass through space 18 provided between cylinder 19 located below the deflector and cylinder 20. The air preheater surrounds said cylinder 20. Conduit 6 and the air preheater are heat insulated by means of insulating casing 29.

In the embodiment of Fig. 4, the hot products, after impinging against deflector 17, flow through annular space 21 and follow the path that is limited by helical elements 22, said products issuing through conduit 23. Air arriving through conduit 28 circulates through space 24 and follows the path limited by helical elements 25. The air preheater, which is separated from the combustion chamber through suflicient thick insulating walls 26, is enclosed in an insulating casing 27.

The chief advantage of this arrangement is to materially reduce the space occupied by the gas generator, which is particularly advantageous when said gas generator is intended to be mounted on a vehicle. 7

Furthermore, the inside of the combustion chamber is separated from the preheater by walls whose thickness may be chosen sufficient for avoiding any exchange of heat between the combustion chamber and the preheater.

Lastly, said preheater improves, by its presence, the heat insulation of the combustion chamber with respect to outer air.

Circulation of air and of the hot gases in parallel currents is an advantageous arrangement, but it should be well understood that my invention is not limitedto generators including that feature.

The dimensions of the combustion chamber and also the distance from the atomizer should be taken into account for obtaining a satisfactory resultfrom the method according to my invention.

For if the combustion chamber is too large, the interval of time during which the gases are submitted to a temperature comprised between 1000 and 1100 C. may be sufficient to cause carbon deposits to appear. On the other hand, if the combustion chamber is too small, combustion takes place under bad conditions and causes the formation of tars. As for the distance of the atomizer from the bottom of the crucible or the deflector, it depends on the degree of atomization, and it may be reduced when the fineness of atomization increases. For instance, I have obtained good results with a distance of 180 mm. between the atomizer and the bottom of the deflector, in a cylindrical chamber having a diameter equal to 145 mm. and using a double atomizer having ten holes of 2 mm. with a slot of 0.5 mm. The air, heated at about 600 0., was fed in the proportiomof 5 litres for 2.2 grams of oil, the diameter of the annular row of holes being about 20 mm. Furthermore, the jets of air were arranged to converge onto a circle having a diameter of 4 mm.

Although I have disclosed what I deem to be the most practical and eflicient embodiments of my invention, I do not wish to be limited thereto as there might be changes made in the arrangement disposition and shape of the parts without departing from the principle of my invention as comprehended within the scope of the appended claims.

What I claim is:

1. Process for the manufacture of gas from heavy oils, which comprises atomizing heavy oil by means of an amount of hot air insuiiicient ior supporting a complete combustion, thus having a partial combustion, controlling the proportions of air and oil so that said partial combustion takes place at a temperature of at least 1000 C., causing the oil thus treated to move as a free jet in an unobstructed zone, thus performing the conversion of said oil to hot gas, removing the hot gas from said zone before the whole oxygen of the air has got combined with the oil and suddenly cooling it down to a temperature of 700 to 900 C.

2. A process of producing gas from heavy oil, which comprises atomizing heavy oil by means of an amount of hot air insufl'icient for supporting a complete combustion so as to obtain a partial combustion, controlling the proportions of air and oil so that said partial combustion takes place at a temperature of at least 1000 C., causing the hot products thus treated to move as a free jet in an unobstructed zone, deflecting said jet of hot products in said zone, and causing said products to pass directly into a strongly cooled zone before the whole of the oxygen of the air has got combined with the oil, so as to suddenly cool said hot products down to a temperature of from 700 to 900 C.

3. A process of producing gas from heavy oil, which comprises atomizing said heavy oil directly into an unobstructed zone by means of an amount of preheated air insuflicient for supporting a complete combustion, so as to obtain a free jet of hot products undergoing a partial combustion, controlling the supply of oil and preheated air so that said partial combustion takes place at a temperature of at least 1000 C., causing said hot products to pass directly into a second zone before the whole of the oxygen of the air has got combined with the oil, cooling said second zone by means of air so as to obtain the preheated air above mentioned, and controlling the interchange of heat of said hot products with said air in said second zone so as to cool the hot products down to a temperature ranging between 700 and 900 C.

CONSTAN'IIN CHILOWSKY.

III 

